Alloy



Patented June 3, 1924.

,TED STATES I'IYRO IYTAKA, or TOKYO, JAPAN, ASSIGNOZR. 'ro MITSUBISHIZOSEN KAISHA, M11, or TOKYO, JAPAN.

...- ALLOY.

No Drawing.

To all who-21bit may concern Be it known that ITYRO IYTAKA, a subject ofthe Emperor of Japan, residing at No. 26 Sanchome Sugamomachi, TokyoPrefecture, Japan, has invented certain new and useful Improvements inAlloys, of which the following is a specification.

This invention relates to a special alloy which contains copper as itslargest constituent and together with nickel, and a small amount ofaluminum.

The object of the invention is to obtain materials practicallyunoxidizable even at high temperatures, and at the same time of greatstrength and fair ductility, so that it can be profitably used forengineering purposes where unusual strength and resistance to heat aredesirable.

The alloy has a great power of resisting corrosion by atmosphericinfluences and by sea Water, and isquite superior in that respect toother similar alloys.

The objects of the invention are accomplished in an alloy of copper withnickel which also contains 11 per cent or less of aluminum. The alloy somade possesses unoxidizability both at ordinary and high temperatures.An alloy of nickel and copper without aluminum is well known. I shallnow describe the manufacture and characteristics of the special alloyembodied in my invention, giving a few examples.

Example 1.Alloy of copper and nickel with aluminum. This is formed byalloying aluminum with copper and nickel alloy. The usual alloy ofcopper and nickel in varyingproportions is always in a single phasesolid solution and can be easily worked, and consequently it is veryextensively employed for various purposes. The alloy containing from 3per cent to 25 per cent of nickel is used for locomotive fire-box platesand boiler tubes the one containing 40 per cent of nickel fb andelectric resistance wires; and that of from per cent to 70 per cent ofnickel content is known under the name of Monel Application filedJanuary 7, 1921.

r thermo unction Serial No. 435,688.

metal and is said to have resisting power against corrosion byatmospheric and sea water, and also to possess great strength so andelongation and is widely used for varied purposes.

After thorough investigations it was found, however, that all of thecopper-nickel alloys were liable to be oxidized consider- 55 ably atcomparatively low temperatures from 400 to 500 C. The oxidation is so'great that they are not proper materials to be used as engineeringmaterials to with stand intense heat, e. g., boiler tubes.

The special alloy of my invention formed of these known alloys with anaddition of suitable amount of aluminum, is much more resistant tooxidation. According to practical tests, the materials have been kept inoxygen gas at 800 C., for more than ten hours, without having beenaffected at all; even the lustre not being lost. It is needless tomention that other alloys, subjected to a similar test, oxidize untilthe material ultimately becomes a rust. This proves the superiority ofthis alloy to be really remarkable.

With regards to strength, elongation and other properties, the newalloys surpass by far, those of the aluminum bronze (alloy of Cu and Alonly) and other similar alloys.

The superior mechanical properties of this special alloy can bedeveloped by special treatment; this alloy, after being cast andannealed, can withstand high stresses, up to 35 tons per square inch,with 15 per cent elongation.

With an adequate proportion of nickel and aluminum, this alloy may haveatensile strength of 30 tons per square inch with an elongation of 30per cent in annealed state. If further mechanical treatment is given,the strength and ductility can be increased even more, and with specialproportions of the three elements contained, the alloy as cast may havea strength of over 50 tons per square inch.

It may be rolled and hammered, and therefore it can be readily andsuccessfully I claim:

Worked. An alloy consisting essentially of 7 4 to One example of thepercentage of the con- 97% of copper, 2 to 11% of aluminum, 1 tostituents of this alloy may be approximately 15% of nickel. 15 5 asfollows:- In testimony whereof he afiixes his signagoplpeir jfrom 37 percent to 74 per cent. ture.

ic e rom .per cent to 15 per cent. Aluminum from 2 per cent to 11 percent. ITYRO IYTAKA' The presence of minor amounts of impuri- Witnesses:10 ties in the constituents does not interfere GENJI KURIBARA,

' with the useful properties above mentioned. C. ARcILLAe.

